body,
html {
  width: 100%;
  height: 100%;
  max-width: 600px;
  padding: 0;
  margin: 0;
  overflow: hidden;
}

body {
  padding: 10px;
  box-sizing: border-box;
  transition: all 1s;
}

div.pic img {
  width: 100%;
}

#modeBtn {
  font-size: 2rem;
  float: right;
  border: none;
  background: transparent;
}
